白藜芦醇对猪前体脂肪细胞凋亡的作用及机理

旨在研究白藜芦醇对猪前体脂肪细胞凋亡的作用,探讨其分子机制。以50 μmol/L、100 μmol/L、200 μmol/L、400 μmol/L白藜芦醇处理猪前体脂肪细胞,采用Hoechst 33258染色剂染色,光学和荧光显微镜分别观察细胞的形态学变化。semi-qRT-PCR和Western blotting方法检测凋亡相关基因sirt1、caspase-3、bcl-2、bax、p53、NF-κB的mRNA和蛋白的表达变化。结果表明,白藜芦醇处理后,前体脂肪细胞出现明显的细胞凋亡,伴随细胞体积缩小,染色质凝集,核质固缩等特征显现,与对照组相比200 μmol/L处理组细胞的凋亡率显著升高 (P＜0.05)。凋亡相关基因sirt1、caspase-3和bax的mRNA和蛋白表达水平显著上调 (P＜0.05),而bcl-2、p53、NF-κB等基因的表达水平明显下调 (P＜0.05)。进一步证实白藜芦醇特异性地增加sirt1的表达活性,而sirt1的上调影响caspase-3和bcl-2家族因子的活性,同时参与调控p53和NF-κB的转录表达。因此,推测sirt1调控凋亡相关因子表达是白藜芦醇诱导前体脂肪细胞凋亡的关键原因。     

瘦素(Leptin )对猪前体脂肪细胞分化及PGC-1α和UCPs mRNA表达的影响

 以体外培养的猪前体脂肪细胞为研究对象,分析瘦素(leptin )对前体脂肪细胞分化及能量代谢相关基因PGC- 1α和UCPs mRNA表达的影响.油红O染色提取结果显示,10～90nmol/L的leptin对猪前体脂肪细胞甘油三酯合成均无显著影响(P>0.05).RT-PCR检测结果表明,30　nmol/L和100nmol/L leptin可显著促进LPL mRNA表达,处理24 h较12 h 作用效果明显(P<0.05);两个浓度的leptin对脂肪细胞分化转录因子C/EBPα和PPARγ2在mRNA水平上均没有明显的影响(P>0.05).对能量代谢相关基因的RT-PCR检测结果表明,30 nmol/L 和100nmol/L leptin 可显著促进PGC-1α和UCP3转录 (P<0.05),30nmol/L leptin可明显提高前脂肪细胞中UCP2 mRNA水平(P<0.05),且作用24h促进效果明显优于12h处理(P<0.05).研究结果提示,leptin不影响猪前体脂肪细胞分化,但可能通过上调PGC-1α和UCPs转录,促进能量消耗.     

pGhrelin对离体猪脂肪细胞Caspase-3活性及基因表达的影响

研究新近发现的猪Ghrelin (porcine ghrelin,pGhrelin)对猪前体脂肪细胞Caspase-3活性及其基因表达的影响．采用细胞培养技术,以仔猪背部皮下前体脂肪细胞为靶细胞,经0、1、10和100 nmol/L pGhrelin处理细胞48 h后,于倒置生物显微镜下进行脂肪细胞形态学观察．利用MTT法测定pGhrelin对细胞增殖的影响．采用分光光度法检测Caspase-3活性．以实时荧光定量RT-PCR方法测定Caspase-3的基因表达．结果显示,10 nmol/L pGhrelin可以显著降低脂肪细胞Caspase-3的活性与mRNA的表达水平(P < 0.05),100 nmol/L pGhrelin对猪脂肪前体细胞增殖有极显著促进作用(P < 0.01)．上述结果表明,pGhrelin可以下调Caspase-3的活性与基因表达,促进脂肪细胞增殖,抑制脂肪细胞凋亡,其机制可能与Caspase-3依赖性凋亡调节信号通路有关．     

EGCG对猪前体脂肪细胞增殖和分化的作用

表没食子儿茶素没食子酸酯（Epigallocatechin-3-gallate,EGCG）是绿茶提取物EGCG的生物活性成分,为了探讨其对猪前体脂肪细胞增殖和分化的影响,以不同浓度EGCG处理猪前体脂肪细胞,MTT法测定EGCG对猪前体脂肪细胞生长的影响;油红O染色检测猪前体脂肪细胞的形态学变化;油红O染色提取法定量分析脂肪细胞充脂量的变化;半定量RT-PCR检测分化转录因子过氧化物酶体增生物激活受体佗（PPARγ2）和CCAAT／增强子结合蛋白α（C／EBPα）mRNA表达水平变化。结果显示：EGCG随着浓度的递增显著抑制猪前体脂肪细胞的增殖（P〈0．01）;低浓度的EGCG（5μmol／L）不影响脂肪细胞分化,而高浓度EGCG（200μmol／L）显著抑制猪前体脂肪细胞分化,同时下调PPARγ2和C／EBPαmRNA表达,本研究结果表明EGCG可抑制猪前体脂肪细胞的增殖和分化。     

视黄酸X受体α促进猪前体脂肪细胞分化

采用细胞转染、油红O染色、油红O染色提取法、GPDH活性测定、semi-qRT-PCR等方法研究了视黄酸X受体α (retinoic acid X receptor α, RXRα)在猪原代前体脂肪细胞分化中的作用及其机理.结果表明,转染pRXRα-EGFP促进了猪前体脂肪细胞RXRα 的表达,脂肪细胞分化能力随之增强, 脂肪细胞GPDH活性、分化转录因子PPARγ和C/EBPαmRNA表达水平均显著升高(P<0.05). 结果提示,RXRα可能通过调控过氧化物酶体增殖物激活受体γ(peroxisome proliferators-activated receptor-γ, PPARγ)和CAAT/增强子结合蛋白家族（CCAAT/enhancer binding proteins, C/EBP）C/EBPα 基因表达变化促进猪前体脂肪细胞分化.     

DZNep诱导HL-60细胞凋亡和生长抑制

[目的]研究S-腺苷同型半胱氨酸水解酶抑制剂DZNep(3-Deazaneplanocin A)对人早幼粒白血病细胞HL-60增殖的影响。[方法]细胞计数法分析DZNep(10~500 nmol/L)处理对HL-60细胞增殖的影响;以DNA片段化、Annexin-V/PI法和线粒体膜电位法检测DZNep处理对HL-60细胞凋亡的影响。Western Blot检测细胞凋亡相关基因Bax和细胞色素C的表达。[结果]50 nmol/L DZNep对HL-60细胞的24、48、72h增殖抑制率达18%、44.5%、81.7%。Annexin-V/PI法显示DZNep能诱导HL-60细胞发生剂量依赖性的细胞凋亡。进一步研究发现,DZNep(50nmol/L)处理24 h诱导23.8%的HL-60细胞发生线粒体途径介导的细胞凋亡,表现为细胞DNA片段化、线粒体膜电位下降和Bax基因表达上调,同时伴有细胞浆内细胞色素C增加。[结论]DZNep能在较低浓度下抑制HL-60细胞增殖并通过激发线粒体凋亡途径诱导HL-60细胞凋亡,具有抗人早幼粒细胞白血病治疗的潜在应用前景。     

磷脂酰肌醇 -3 激酶不直接调控PC12 细胞的分泌

磷脂酰肌醇-3激酶(PI3K)是磷脂酰肌醇代谢过程中一种重要的酶,通过其代谢产物参与了对多种细胞生理活动的调节,如囊泡运输、细胞骨架重组、细胞存活、吞噬作用、细胞凋亡等.为研究其对细胞分泌功能的作用,使用磷脂酰肌醇-3激酶家族的特异性抑制剂渥曼青霉素(wortmannin)阻断磷脂酰肌醇-3激酶的活性,以EGFP-2xFYVE融合蛋白与磷脂酰肌醇-3-磷酸(PtdIns-3-P)的结合为指征,使用荧光显微成像技术检测渥曼青霉素对磷脂酰肌醇-3激酶的抑制作用,采用膜片钳膜电容测量方法及光解钙离子释放技术检测渥曼青霉素对PC12细胞分泌功能的影响.实验结果表明,wortmannin阻断了磷脂酰肌醇-3激酶的活性,抑制了磷脂酰肌醇-3-磷酸(PtdIns-3-P)的产生,并使FYVE与PtdIns-3-P解离,但渥曼青霉素处理之前和处理30 min后的PC12细胞分泌反应的幅度、动力学特性和分泌的钙依赖性均无显著差异,表明磷脂酰肌醇-3激酶对PC12细胞的分泌无显著的直接影响.     

全反维甲酸协同增强阿霉素对去势抵抗前列腺癌的疗效

[目的]探究全反维甲酸与阿霉素联用对去势抵抗前列腺癌的疗效。[方法]以PC3细胞作为去势抵抗前列腺癌细胞模型,MTT法检测联合用药对细胞的增殖抑制效果;流式细胞仪检测联合用药对细胞凋亡和细胞周期的影响;反转录PCR检测联合用药对凋亡相关基因表达的影响。[结果]2μmol/L全反维甲酸与80 nmol/L阿霉素联用协同增强对PC3细胞的抑制效果(为51.2±1.41%),与单独用药存在显著性差异(P0.05),促进PC3细胞的凋亡(为17.80±0.54%),同时阻滞细胞的G1和G2期,上调Bax及caspase 3基因的表达,下调Bcl-2基因的表达。[结论]全反维甲酸与阿霉素联用可增强对PC3细胞的增殖抑制和凋亡效果,Bcl-2、Bax及caspase 3基因参与了联合用药诱导PC3细胞凋亡的调控,从而增强对PC3细胞的疗效。     

肝刺激因子促进过氧化氢诱导的肝星形细胞凋亡

目的肝刺激因子(hepatic stimulator substance, HSS)可以抑制肝纤维化,而且在肝星形细胞中表达,但是其在肝星形细胞中的作用尚不清楚。因此本研究探讨肝刺激因子对肝星形细胞凋亡的影响,从而为研究HSS抑制肝脏纤维化的机制奠定基础。方法选择人肝星形细胞系LX-2作为研究对象,利用瞬时转染的方法构建过表达HSS的细胞模型后,使用2.5μmol/L H_2O_2刺激细胞20min诱导细胞凋亡;利用Hoechst 33342染色、TUNEL染色、Annexin V-FITC/PI流式细胞术检测细胞凋亡,caspase 3/7活性检测试剂盒检测caspase 3/7活性,进而分析HSS对LX-2细胞凋亡的影响。结果在H_2O_2刺激下,过表达HSS的细胞与转染对照质粒细胞相比,Hoechst 33342染色显示细胞凋亡数目增多,TUNEL染色阳性细胞数增多,流式细胞术检测Annexin V和PI双阳性细胞数显著增多,caspase 3/7活性显著性升高。结论 HSS可以促进H_2O_2诱导的肝星形细胞凋亡。     

烟酰胺在原代培养的猪前体脂肪细胞增殖分化中的作用

为研究烟酰胺(Nicotinamide,NAM)在原代培养的猪前体脂肪细胞增殖分化中的作用,探讨其作用的分子机制,用不同浓度(0-500μmol/L)的NAM处理猪前体脂肪细胞。MTT和油红O染色及提取法检测结果表明:在不同的作用时间内,与对照组相比,100-500μmol/L的NAM均可以促进猪前体脂肪细胞的增殖分化,随着NAM浓度的增加,其对前体脂肪细胞增殖分化的促进作用逐渐上升,当浓度为300μmol/L时达到高峰,即300μmol/L NAM的促进效果最为显著(P<0.05);随后,400和500μmol/L NAM的促进作用逐渐减弱。RT-PCR法分析结果表明,Sirt1 mRNA表达显著下降(P<0.05),而其靶基因FoxO1和脂肪细胞分化标志基因PPARγ2、C/EBPα mRNA表达量明显升高(P<0.01),aP2和LPL表达也显著增加(P<0.05)。表明NAM是Sirt1的一个有效抑制剂,它可能通过抑制Sirt1的表达来促进猪前体脂肪细胞增殖和分化。     

Plant derived coumestrol phytochemical targets human skin carcinoma cells by inducing mitochondrial-mediated apoptosis,cell cycle arrest,inhibition of cell migration and invasion and modulation of m-TOR/PI3K/AKT signalling pathway

The current study was undertaken to investigate anticancer activity of coumestrol phytoestrogen against human skin cancer. MTT assay was performed for cell viability assessment and clonogenic assay for cell colony formation assessment. Apoptosis was analysed by Annexin V/FITC staining, AO/EB staining and western blotting assays. Effects on the m-TOR/PI3K/AKT signalling pathway were investigated by western blotting. Results indicated that coumestrol induced significant toxicity in human skin cancer cells in contrast to mouse skin cancer cells. The proliferation rate in normal skin cells remained almost intact. Annexin V-FITC and AO/EB staining assays indicated coumestrol induced cytotoxicity in skin cancer cells is mediated through apoptosis stimulation. The apoptosis in skin cancer cells was mediated through caspase-activation. Cell migration and invasion was inhibited by coumestrol in human skin cancer cells via inhibition of MMP-2 and MMP-9 expressions. Moreover, m-TOR/PI3K/AKT signalling pathway in SKEM-5 cells was blocked by coumestrol.     

Comparison of anti-apoptotic signalling by the insulin receptor and IGF-I receptor in preadipocytes and adipocytes

We compared the effectiveness of insulin receptor (IR) and type I insulin-like growth factor (IGF) receptor (IGFR) cytoplasmic domains in mediating anti-apoptotic effects in 3T3-L1 preadipocytes and adipocytes. We used TrkC/IR and TrkC/IGFR chimeras, stably expressed in these cells and stimulated with neurotrophin-3 (NT-3), so as to avoid interference from endogenous receptors. After 24-h serum deprivation, 10% of preadipocytes and 2% of adipocytes appeared apoptotic as determined by fluorescence-activated cell sorter (FACS) analysis of cells stained with propidium iodide (PI) and Annexin V. When NT-3 was added, the two chimeras inhibited apoptosis to the same extent by 80% in preadipocytes and 50% in adipocytes. Mutation of juxtamembrane tyrosines (IR Y960F, IGFR Y950F) abrogated these anti-apoptotic effects. Qualitatively similar results were obtained by determination of viable rather than apoptotic cells. We conclude that IR and IGFR have equal potential to inhibit apoptosis in cell backgrounds, which are normally responsive to either IGF-I or insulin.     

Effects of different cryoprotectants on the viability and biological characteristics of porcine preadipocyte

Effective techniques for the cryopreservation of porcine preadipocytes could increase the usefulness of these cells as a model in obesity studies. The objective of this study was to test the effects of the following cryoprotective agents (CPAs) on the cytotoxicity, post-thaw survival, proliferation and differentiation capacity of porcine preadipocytes: ethylene glycol (EG), dimethyl sulphoxide (Me2SO), polyvinylpyrrolidone (PVP), Me2SO+PVP, and no-CPA. In addition to the CPAs, the CPA medium contained 80% DMEM/F12 plus 10% FBS. Trypan blue exclusion tests showed that among the CPA treatments in this study, only EG was toxic to porcine preadipocytes. The highest survival rate (94.96%) and cell viability were obtained when preadipocytes were cryopreserved with 10% PVP. Morphologically, PVP cryopreserved preadipocytes resembled fibroblasts and most underwent attachment, proliferation, and growth arrest with subsequent accumulation of intracellular lipid droplets before becoming mature adipocytes. There were no significant differences in the GPDH activity between adipocytes in the PVP treatment and primary cells from days 3 to 10 of the culture. Analysis of RT-PCR confirmed that there was no significant difference of PPARgamma2 mRNA levels between the cells in the 10% PVP treatment and primary cells. In summary, porcine preadipocytes cryopreserved with DMEM/F12 medium containing 10% PVP and 10% FBS have high survival rate and proliferation potential. Furthermore, the cryopreserved cells synthesize a range of markers that are consistent with this cell type. We conclude that 10% PVP is a suitable CPA for porcine preadipocytes.     

海兔素对人乳腺癌SK-BR-3细胞的抑制作用及机制研究

本文阐述了海兔素(Aplysin)对人乳腺癌SK-BR-3细胞增殖和凋亡的影响,并探讨了其可能的作用机制.分别采用CCK-8法和流式细胞术Annexin V-FITC/PI双染法测定不同剂量海兔素对SK-BR-3细胞的增殖抑制和凋亡诱导作用,并以Western blot测定SK-BR-3细胞中EGFR、Akt及ERK表达水平和磷酸化水平.结果发现,20、30、40、45、50、55、60 mg/L海兔素处理SK-BR-3细胞24 h后,细胞的生长增殖明显受到抑制,呈量效依赖性,其IC25和IC50值为分别为29.4和33.7 mg/L; IC25和IC50剂量海兔素可明显诱导细胞凋亡,并下调SK-BR-3细胞EGFR、Akt及ERK的磷酸化蛋白表达水平,但是不影响总蛋白表达水平.表明海兔素对人乳腺癌SK-BR-3细胞具有抑制增殖和诱导凋亡的作用,其作用机制可能与海兔素抑制细胞中EGFR蛋白磷酸化,进而阻断下游效应分子Akt和ERK的活化有关.     

Green Tea Polyphenol Epigallocatechin Gallate Inhibits Adipogenesis and Induces Apoptosis in 3T3‐L1 Adipocytes

Objective: Green tea catechins have been shown to promote loss of body fat and to inhibit growth of many cancer cell types by inducing apoptosis. The objective of this study was to determine whether epigallocatechin gallate (EGCG), the primary green tea catechin, could act directly on adipocytes to inhibit adipogenesis and induce apoptosis. Research Methods and Procedures: Mouse 3T3‐L1 preadipocytes and mature adipocytes were used. To test the effect of EGCG on viability, cells were incubated for 3, 6, 12, or 24 hours with 0, 50, 100, or 200 μM EGCG. Viability was quantitated by MTS assay. To determine the effect of EGCG on apoptosis, adipocytes were incubated for 24 hours with 0 to 200 μM EGCG, then stained with annexin V and propidium iodide and analyzed by laser scanning cytometry. Both preadipocytes and adipocytes were also analyzed for apoptosis by terminal deoxynucleotidyl transferase dUTP nick‐end labeling assay. To determine the effect of EGCG on adipogenesis, maturing preadipocytes were incubated during the 6‐day induction period with 0 to 200 μM EGCG, then stained with Oil‐Red‐O and analyzed for lipid content. Results: EGCG had no effect on either viability or apoptosis of preconfluent preadipocytes. EGCG also did not affect viability of mature adipocytes; however, EGCG increased apoptosis in mature adipocytes, as demonstrated by both laser scanning cytometry and terminal deoxynucleotidyl transferase dUTP nick‐end labeling assays. Furthermore, EGCG dose‐dependently inhibited lipid accumulation in maturing preadipocytes. Discussion: These results demonstrate that EGCG can act directly to inhibit differentiation of preadipocytes and to induce apoptosis of mature adipocytes and, thus, could be an important adjunct in the treatment of obesity.     

miR-362靶向ZNF644基因调控猪未成熟支持细胞的增殖和凋亡

睾丸组织中未成熟支持细胞的增殖能力决定成熟支持细胞的数量,进而制约成年雄性动物的精子生成能力。研究表明microRNA (miRNA)参与调控猪未成熟支持细胞的增殖和凋亡,但大部分鉴定出的miRNA功能仍不明确。本文基于前期RNA-seq数据筛选结果,研究了miR-362对猪未成熟支持细胞增殖和凋亡的调控作用。首先利用生物信息学方法预测miR-362的靶基因,通过qRT-PCR技术检测miR-362和ZNF644基因在不同发育阶段的猪睾丸组织中的表达水平以及在猪未成熟支持细胞中过表达或抑制表达miR-362后ZNF644基因的表达水平,采用双荧光素酶报告基因系统验证miR-362与ZNF644基因之间的靶向关系。结果显示,miR-362与ZNF644基因3′UTR具有一个潜在的结合位点,miR-362和ZNF644基因在猪睾丸组织中的mRNA表达水平显著负相关(r=-0.723, P<0.01),miR-362和psiCHECK2-ZNF644-WT 3′UTR共转染组的双荧光活性显著降低,且miR-362显著调节ZNF644基因的表达水平,表明miR-362靶向ZNF644基因并抑制其表达水平。为进一步检测过表达miR-362或抑制表达ZNF644基因对猪未成熟支持细胞增殖和凋亡的影响,通过流式细胞术检测细胞周期,CCK8和EdU试剂盒检测细胞增殖情况,Annexin V-FITC/PI方法和qRT-PCR技术检测细胞凋亡情况及凋亡相关基因的表达水平。结果表明,过表达miR-362后,猪未成熟支持细胞周期被阻滞在G₁期,抑制表达ZNF644基因后,猪未成熟支持细胞被阻滞在G₂期,细胞增殖能力显著减弱,细胞凋亡率显著提高,细胞凋亡相关基因呈促进凋亡的差异表达。本研究结果证实miR-362靶向ZNF644基因抑制猪未成熟支持细胞的增殖而促进其凋亡,为深入研究miR-362在猪精子生成过程中的生物学功能提供了理论基础。     

紫丁香苷调控PI3K/Akt/mTOR信号通路诱导乳腺癌细胞凋亡的研究

目的 研究紫丁香苷的抗乳腺癌作用及分子机制，为紫丁香苷的临床应用提供理论依据。方法 MTT检测紫丁香苷对乳腺癌细胞增殖的抑制作用；台盼蓝、TUNEL和Annexin V-FITC/PI染色检测细胞的凋亡状况，Western bolt检测Caspase-3的活化情况，判断细胞凋亡是否发生；检测凋亡相关蛋白B淋巴细胞瘤2（Bcl-2）的表达，结合JC-1染色探讨紫丁香苷对线粒体凋亡途径的影响；运用PI3K激动剂Recilisib做对比，qRT-PCR和Western bolt检测紫丁香苷调控PI3K/Akt/mTOR通路诱导癌细胞凋亡的作用。结果 紫丁香苷对乳腺癌细胞的增殖具有时间和剂量依赖的抑制作用，能诱导癌细胞发生凋亡。进一步研究发现，紫丁香苷处理后，细胞内Caspase-3被激活，Bcl-2表达下降，线粒体膜电位明显丧失，PI3K、Akt和mTOR的mRNA与蛋白质水平表达无明显变化，但蛋白质磷酸化水平明显下降；Recilisib处理后部分抵消了紫丁香苷对乳腺癌细胞凋亡的作用。结论 紫丁香苷对乳腺癌细胞MDA-MB-231和MCF-7具有良好的抑制作用，其通过抑制PI3K/Akt/mTOR信号通路的活化来抑制细胞增殖并诱导细胞发生线粒体途径的凋亡。紫丁香苷是具有开发潜力的抗乳腺癌药物。     

TNFalpha is a potent inducer of platelet-activating factor synthesis in adipocytes but not in preadipocytes. Differential regulation by PI3K

Tumour necrosis factor alpha (TNFalpha) induces platelet-activating factor (PAF) synthesis in many inflammatory cells. Here, we investigate the possibility that TNFalpha stimulates PAF synthesis in rat adipocytes and preadipocytes and that phosphoinositide 3-kinase (PI3K) and extracellular signal-regulated kinase 1/2 (ERK1/2) are implicated in this process. Primary cultures were incubated with [3H]lyso-PAF and stimulated by TNFalpha in the presence or absence of wortmannin. We found that, although both cultures synthesized PAF at a similar basal rate, TNFalpha-induced PAF synthesis in adipocytes was 7-fold higher than in preadipocytes. This suggested a maturation of PAF-TNFalpha interrelationship during adipocyte differentiation. Wortmannin enhanced TNFalpha-dependent PAF synthesis in adipocytes but not in preadipocytes, indicating the negative control by PI3K in mature cells. PAF increase was due to the regulation of its biosynthesis since PAF-acetylhydrolase (PAF-AH) activity was TNFalpha- and wortmannin-independent. Our hypothesis is that PAF mediates TNFalpha inflammatory effects in both adipocytes and preadipocytes and that this pathway is enhanced during adipocyte differentiation, a mechanism which is highly active during the development of obesity.     

花生四烯酸对大鼠前体脂肪细胞生长与分化的影响(英文)

以大鼠前体脂肪细胞原代单层培养为模型,用不同浓度花生四烯酸(AA)处理细胞.通过台盼蓝排斥试验及噻唑蓝比色法(MTT)反映各组细胞增殖状况;Hoechst33342荧光染色观察AA处理后细胞核形态变化;油红O染色提取法分析细胞分化程度;逆转录聚合酶链反应(RTPCR)分析环氧合酶2(COX2)mRNA表达情况,探讨外源性AA对大鼠前体脂肪细胞生长分化的影响及其可能机制.120μmolLAA处理前体脂肪细胞24～72h,细胞活力明显高于对照组;160μmolLAA作用48h时,前体脂肪细胞表现出明显的凋亡现象;脂肪细胞经40～80μmolLAA作用72h时,细胞油红O染色的吸光度值显著减少;40μmolLAA在作用的24h时,可显著上调COX2mRNA的表达量.说明外源性AA以时间性和剂量依赖性调节前体脂肪细胞的生长与分化,40～80μmolLAA在不显著增加脂肪数目的同时,可抑制前体脂肪细胞向成熟脂肪细胞转化、减少脂肪生成量,对控制动物体脂的形成有一定参考价值,COX2mRNA表达量的上升可能是AA抑制前体脂肪细胞分化的内在机制.